sys/xdr/xdr_reference.c

   1 /*      $NetBSD: xdr_reference.c,v 1.13 2000/01/22 22:19:18 mycroft Exp $ */
   2
   3 /*
   4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   5  * unrestricted use provided that this legend is included on all tape
   6  * media and as a part of the software program in whole or part.  Users
   7  * may copy or modify Sun RPC without charge, but are not authorized
   8  * to license or distribute it to anyone else except as part of a product or
   9  * program developed by the user.
  10  *
  11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  14  *
  15  * Sun RPC is provided with no support and without any obligation on the
  16  * part of Sun Microsystems, Inc. to assist in its use, correction,
  17  * modification or enhancement.
  18  *
  19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  21  * OR ANY PART THEREOF.
  22  *
  23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  24  * or profits or other special, indirect and consequential damages, even if
  25  * Sun has been advised of the possibility of such damages.
  26  *
  27  * Sun Microsystems, Inc.
  28  * 2550 Garcia Avenue
  29  * Mountain View, California  94043
  30  */
  31
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 static char *sccsid2 = "@(#)xdr_reference.c 1.11 87/08/11 SMI";
  34 static char *sccsid = "@(#)xdr_reference.c      2.1 88/07/29 4.0 RPCSRC";
  35 #endif
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38
  39 /*
  40  * xdr_reference.c, Generic XDR routines impelmentation.
  41  *
  42  * Copyright (C) 1987, Sun Microsystems, Inc.
  43  *
  44  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
  45  * "pointers".  See xdr.h for more info on the interface to xdr.
  46  */
  47
  48 #include <sys/param.h>
  49 #include <sys/systm.h>
  50 #include <sys/malloc.h>
  51
  52 #include <rpc/types.h>
  53 #include <rpc/xdr.h>
  54
  55 /*
  56  * XDR an indirect pointer
  57  * xdr_reference is for recursively translating a structure that is
  58  * referenced by a pointer inside the structure that is currently being
  59  * translated.  pp references a pointer to storage. If *pp is null
  60  * the  necessary storage is allocated.
  61  * size is the sizeof the referneced structure.
  62  * proc is the routine to handle the referenced structure.
  63  */
  64 bool_t
  65 xdr_reference(XDR *xdrs,
  66     caddr_t *pp,                /* the pointer to work on */
  67     u_int size,                 /* size of the object pointed to */
  68     xdrproc_t proc)             /* xdr routine to handle the object */
  69 {
  70         caddr_t loc = *pp;
  71         bool_t stat;
  72
  73         if (loc == NULL)
  74                 switch (xdrs->x_op) {
  75                 case XDR_FREE:
  76                         return (TRUE);
  77
  78                 case XDR_DECODE:
  79                         *pp = loc = (caddr_t) mem_alloc(size);
  80                         if (loc == NULL) {
  81                                 printf("xdr_reference: out of memory");
  82                                 return (FALSE);
  83                         }
  84                         memset(loc, 0, size);
  85                         break;
  86
  87                 case XDR_ENCODE:
  88                         break;
  89                 }
  90
  91         stat = (*proc)(xdrs, loc);
  92
  93         if (xdrs->x_op == XDR_FREE) {
  94                 mem_free(loc, size);
  95                 *pp = NULL;
  96         }
  97         return (stat);
  98 }
  99
 100
 101 /*
 102  * xdr_pointer():
 103  *
 104  * XDR a pointer to a possibly recursive data structure. This
 105  * differs with xdr_reference in that it can serialize/deserialiaze
 106  * trees correctly.
 107  *
 108  *  What's sent is actually a union:
 109  *
 110  *  union object_pointer switch (boolean b) {
 111  *  case TRUE: object_data data;
 112  *  case FALSE: void nothing;
 113  *  }
 114  *
 115  * > objpp: Pointer to the pointer to the object.
 116  * > obj_size: size of the object.
 117  * > xdr_obj: routine to XDR an object.
 118  *
 119  */
 120 bool_t
 121 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
 122 {
 123
 124         bool_t more_data;
 125
 126         more_data = (*objpp != NULL);
 127         if (! xdr_bool(xdrs,&more_data)) {
 128                 return (FALSE);
 129         }
 130         if (! more_data) {
 131                 *objpp = NULL;
 132                 return (TRUE);
 133         }
 134         return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
 135 }